POU2AF1 and primary biliary cholangitis: In addition, GWASs in the Japanese population identified three novel PBC susceptibility loci, including tumor necrosis factor superfamily member 15 (TNFSF15), POU domain class 2 associating factor 1 (POU2AF1), and protein kinase C beta (PRKCB), which have not been identified in European descent16,17.